In the case of the electronic watch, there is generally employed an electromagnetic motor with a bipolar permanent magnet operating in a stepping mode, the rotor effecting a rotation of 180.degree. per step. If the watch includes a seconds hand and the frequency of the steps is 1 Hz, it is then necessary to have a reduction by a factor of 30 between the rotor of the motor and such hand. The rotation of the rotor through 180.degree. per step thus necessitates a gearing system serving for such reduction which brings about losses of energy essentially due to friction and generates a relatively substantial noise.
In a general manner, in order to obtain a quasi continuous stepping rotation with a bipolar permanent magnet, it is necessary to increase the frequency of operation of the motor and to provide a reduction mechanism between the rotor of such motor and the arrangement driven by such motor. This inevitably brings about additional energy losses and an increase in the costs of manufacture.
A purpose of the present invention is to provide an electromagnetic transducer enabling a stepping operation with a small angular displacement of the rotor per step.
A second purpose of the invention is to provide such an electromagnetic transducer capable of being easily miniaturized for a relatively low cost while possessing a good energy yield.
Finally, a third purpose of the invention is to provide such an electromagnetic transducer exhibiting a compact structure which assures a good yield relative to the useful energy and the volume of said transducer.